Networked control systems are a ubiquitous trend in commercial, industrial and institutional business markets and also in consumer markets. Examples of networked control systems are building automation systems, e.g. for lighting, heating and ventilation or safety. A networked control system may consist of devices like light ballasts, switches, daylight or occupancy sensors, actuators or meters. A networked control system also comprises a home control system for controlling for example media devices, which are connected to a network in the home and may be accessed and controlled via for example a web interface by means of another device such as a computer or network remote controller. The devices are preferably connected wirelessly, i.e. via RF (radio frequency) modules.
An example of a networked control system is the Light Master Modular (LMM) product line of the Applicant. LMM allows controlling of lamps in one or multiple rooms. A special version of LMM is controllable over a TCP/IP network connection remotely. In order to enable a comfortable control, a room controller with its IP-address must be bound to user interface devices being in the same room. However, one problem is that the user interface device has to get notified, when ever the room controller gets a new IP address, e.g. by means of a DHCP service, or a name server has to translate the controller name into the correct IP address. Another problem is that the user interface device may be moved to a different room but still controls devices in the original room, because the user interface device is still bound to the room controller of the original room.
US2005/0190768A1 addresses these problems and suggests to transmit the network address assigned to a device located in a delimited space to another discovering device not via the common network of the devices in the space, but in a manner that substantially limits its reception to the delimited space, for example by using infrared (IR) signals. When the discovering device receives such a signal containing the address of the discoverable device in the delimited space, it can establish a communication via the common network with the discoverable device that transmitted the address. Thus, discovery is limited to discovering devices residing in the delimited space also containing the discoverable devices.